Signal system for railways.



No. 889,561. PATL1VI"EDv JUNE 2, 1908.

L. HLTHULLBN, SIGNAL SYSTEM FR RAILWAYS.

APPLICATION FILED MAR. 3, 1906.

' citizen of the United States, residing tiran srarns rarer irren.

LOUIS H. TI-IULLEN, OF EDGEWOOD,l PENNSYLVANIAASSIGNOR TO THE UNION SWITCH 8; SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

'SIGNAL SYSTEM FOR RAILWAYS.

iva 889,561.

To all whom it may concer/n: j

Be it known that I, LOUIS II. THULLEN, a at Edgewood, in the county of Allegheny and State of Pennsylvania, have invented certain'new and useful Improvements in Signaling Systems for Railways, of which the fol owing is a specification.

My invention relates to signaling systems foi' railways and especially to railways, the track rails of which are included in and form part of the return path or conductor to the generator for the current eniployedffor propelling motor cars along the railway.

I will describe a signaling system embodying `my invention and then point out the novel features thereof in claims.

The accompanying drawing, is a diagrammatical representation of a portion of an electric railway, the track rails of which are divided by insulation to form block or track sections and are used as a part of the return path or conductor to the generator of the -propulsion current, and a signaling system applied thereto and embodying my invention.

Referring now to the drawing, A designates a portion of a railway which is divided into sections, X, Y, Z, etc. These sections are generally termed block or track sections and I will hereinafter refer to them as block sections. These block sections are formed by inserting insulation a in some forni at determined points in one or both of the track rails, the one arrangement being the equivalent of the other so far as block sec-n tioning is concerned, and both being well known in the art. In the drawing I have shown insulation a'i'nserted in both of the track rails.

.r, .r1 designate the track rails of block section X, y, y the track rails of block section Y,

and so on.

P designates a generator of current for propelling the cars, which may be either an A. C. generator or a D. C. generator.

l designates a trolley or third iail connected with one pole of the power generator and extending along the railway in a usual and well known manner.

As the track rails'of the railway, one orl both, are to form part of the return path or conductor for the propulsion current employed for the motor cars and still contain insulation to form block sections, I make pro- Speccation of Letters Patent. t

Application filed'March 3, 1906. Serial No. 303,945.

Patented `Tune 2, 1908.

vision for conducting the car propulsion current from the track rails of one block section to the track rails of an adjacent block-section, around the points of insulation. This I accomplish by means of inductive bonds, lo-

cated at the insulated points which inductive which is also dia animatically illustrated in I my applications led February 5th, 1904, Serial Nos. 192,145 and 192,146. These inductive bonds Generally stated each comprise a laminated` iron core which may or may not have an open magnetic circuit and a co per winding of few turns. The ends of t e winding of ya bond are connected with the two track rails of the block section, and a conductor ext-ends from the middle of the winding, and which conductor is arranged to be .connected to the middle winding of -an adjacent boned.

In the drawing I have diagrammatical'ly illustrated the bonds and their connections.

B, B1, B2, B3, etc. designate the bonds.

b designates the core and b1 a winding surrounding a leg of the core.

b2 designates a conductor joining the mid- This dle oints of two adjacent windings.

point 0I the -i con( uctor as will be seen may be common to coiiductor T and after passing through the car motors to the rails will flow through the rails and winding of the bonds in the direction indicated by the plain arrows. It will be seen that the propulsion current in its passage through the windings of the bonds fiows in at their ends and out at its middle point or in at its middle point and out at its ends in reverse or opposite directions, the result beine that the core is not appreciably inagi'ietize( so that the bond may be'used as a path of i niped ance for alternating signaling The track rails of.

' 192,145 and 192,146.

currents which inay be usedjrrthe track circuits. This has been all set forth in my ap lications hereinbefore referred to, Serial Nibs. It will also .be seen that the pro ulsion current flows in the same direction in oth traffic rails of a block section and in the saine direction through all the block serztions The foregoing, it will be seen, is directed more particular.T to the arrangement of the track in the lreturn path or conductor of power'v circuit whereby the pro ulsion current ows along it yet it is divide into insulated sections to forni the block sections of the signaling system.

In'tliesignaling system I employ a track circuitfor each block section which, as usual, comprises a source of si naling current, a relay and the rails of the lock section or porlto the signaling current or it maybe so rotected bythe apparatus devices Wiicli will prevent its being operated by tle pro: pulsion current. i

Pl designates a generator of alternating signaling current, p, p1, feeder mains extending from the generator along the line of rail- -way and Q, Q1, Q2, etc. ste -down transformers. 'The primary win ings of these transformers are in multiple circuit with the feeders p, p1, and their secondary windings are connected with the track rails ofthe block sections. One such transformer is provided for each block section and-is the source of signaling current for the track circuit of the block section. 4

R, R1,- etc. desigpate relays, one beine provided for the trac vcircuit of each block section. The construction of these relays is such that they will only res ond to the-alternating signaling current. `f necessary, suitable apparatus or devices may be employed to protect theielay against the action of the propulsion current. 'Y A form of relay which may be used is illustrated in my `application filedoctober 13, 1903, Serial No. 176,836.

rlhe track circuit for a block section, foreX= `ample`ll'r'ick-section X, may be rtracedas follows: Starting from one terminal of the' seeondary windmg of the transformer for that Y block section it is, wire 1, track rail x1, wire 2 coils of the relay, wire 3, track rail :r and Wire to the other terminal of the seconder i winding. The How of the alternating signa eeasei current is indicated by the featliered'arunderstood in the art.- Each local circuit naling current of a track circuit is present in the coils of the relay included in that circuit the relay` responds to keep closed the local circuit and thereby causes the semaphore or other signal device of the railway signal to indicate a safety condition. Vthemhowever, the alternating signaling current is absent from the coils of the relay, as when it is .short circuited by the wheels and axles of a car upon the rails of the track circuit, the relay responds to open the local circuit and causes A the sema hore to indicate'a danger condition.

This is a well understood 'in t e art.

The point of location of the transformer in the track circuit, the type of relay employed as Well as the manner of energizing the coils vof therelay frornthe alternating signaling current in the track circuit is immaterial so far as my invention is concerned. All that is required is that the relay shall'respond to control a railway signal as to one of its operations by the alternating signaling current of the track circuit when no train is in a block section and to another operationgof the railway signal when the relay is not energized by the alternating signaling current of the track circuit, for example, when the alternating signaling current 1s shunted from it by the wheels and axle of .a car.

As both trackrails of a block section are insulated at-its ends from the track rails of ad'acent block sections, the alternating signaling current inone block section will not react on or affect the altgrnating signaling current of an adj acent`block section. In other words, the several track circuits ofthe block sectionare electrically independent of one another by reason of the insulations c. Inthe event, however, that one or both of thejnsulations a between two adjacent block sections should break down to suchan extent vas to establish an electrical connection between the two adjacent rails at that point it may be possible that the alternatmo signaling current of one block section would find a path through the rails wherethe insulation' had broken down and thus effect the rela of ono or both of the block sections to have 1t in turn control a railway signal to give a falsey indicatirni. 'lo guard against this, in the present 'invention I provide means Which, when an insulation c breaks down, controls a railway signal, for' example, opens a local circuit, and thus have the railway signal posi tively give a danger indication. The means which preferably employ is a relay, one being located between veach two adjacent block sections. As shown, this relay is actuated to keep a local circuit closed by the difference of potential existing at the ends of the track rails of two adjacent block sections, which'difference of potential is due to the alternatingsignaling currents flowing in the two vtrack circuits of the adjacent block sections, and to open a local circuit wherein this difference of potential is destroyed, due to the breaking down of one or more insulations at this point. The connections of the transformers with the rails of the several block sections are. such that at any given instant the polarity of the alternating signaling current of one. track circuit is opposite at the same instant. to the polarity of the alternating signaling current inthe adjacent track circuits. lor'examplmin block section Y, the polarity of the track rails at any one instant is indicated bythe usual signs at the ends of the track rails and the direction of [low of the alternating signaling current is indicated by the feathered arrows at one instant. Atvthe same instant, the polarity of the track rails in the adjacent block sections also indicated by the usual signs, and the direction of [low of alternating signaling` cur-` renty is also indicated by the feathered arrows.

A ,It will be understood, of course, thatat the next instant, by reason of the use of an alternating signaling current in the track circuits` the polarity of the rails will be reversed, as

will also be thc direction of flow of the current' in the. several track circuits. .For simplicity and clearness I have only illustrated the polarity of the rails of a block section at'one instant. lhus it will be seen that at the ends of the track rails of two adjacent block sections there will be a difference of potential due to the alternating signaling current inl the two adjacent track circuits.

E, E1, etc.V designate the means hereinbefore referred to, which I have stated are preferably in the form of a relay. In fact it is a type of motor the yarmature of which carries an arm e1 controlling'one or more contacts comprised in a local circuit of a railway signal, and which motor coni rises a field coil e and an armature coil e1 in fioth of which current has to flow simultaneously in the'same direction to have it move its armature inl one direction. A reversal ofthe flow of current in one or thc other of the windings or no flow of current in one or the other of its two Windla wire 1-2, and the other terminal with an end of the other track rail in block section Y by a Wire 13. l Thus a circuit through both coils of thel relay E will be established, each of which circuits may be traced as follows: Starting from Wire 1 of a transformer Q, Q1, etc. in a block section (for example Q1), it is, track rail y, wire 13, armature 4coil e1, wire 12, track rail fc, wire 4, transformer Q, Wire/ l, track rail wire 10, coil e, wire 1 1, track rail y1 and wire 4 to transformer. It will 'benoted that this circuit has vthe voltage of two trans-y formers Q, Q1. It will also be noted that a track relay: is supplied with signaling current from the transformers of two clock sections, but the track relays are of such design thatwhen one transformer is short circuited from it, the relay will not release its armature to open the 'signal circuit as it will yet have current from one transformer which will be sufficientI -to hold closed the contact c1. The same may be true of the relays E, E1, etc.

lIn'the event that the relays E, E1, etc. be designed to open a local circuit when one of their operating transformers is short circuited, the signaling system illustrated is what is termed an overlap system. For example, a train in block section X short vcir- .cuits current from the transformer Q from the track relay R and relay E, causing these relays to have their armatures move to'open the local-circuit of railway signal S so that the signalA device thereof wil move to a. position indicating danger.

When the car or train soA moves out of block section X,`and into block section Y, transformer Q1 of block section Y.

is short circuited from the track relay R1 and the relay E1, thus opening the local circuit onrailway s'gnal S1 sothat lts signal device will move to a position indicating danger. The short circuiting by the train in block section Y of the transformer Q1 also aects the relay E, which being de rived of the current and voltagefrom one o for its operation, does not move its armature to close the local circuit of railway signal S. Thus Ithe signal device of a railway signal will be held apositiori indicatinr danger so long as a car or tram sinthebclock section guarded. by that railway signal or in the block section next in advance.

" Suppose now that the insulation between the track rails and'y ofl block sections X and Y should break down tosuch an extent as to the transformers required izo rail x1, wire 10, coil e, wire 1l, rail y1 and wire i 4 to transformer Q1.

In the event that the insulatirjn between rails x1 and y1 broke down -to an extent to `form an electrical ath between these two rails, then the lie d coil e1 would be short circuited, and as no current .would flow in it, the armature would again move to open the local circuit of railway sig-l nal S. In the event that both insulations aJ should break down sufficiently to establish electrical paths between the track rails of the two block sections the track relays as well as the relays E, E1, etc. operated from the trans.-

formers `Q, Q1, of these block sections would operate to open the local circuits of the railway signals 1n which they are included.

' I do not limit. myself to this particular type of relay as itis a arentthat any relay or several relays,- coulpdp be used, that would be operated in one directionl` (to close av circuit on a railway signal) by the difference of potential of the signaling. current in the rails at the ends of two adjacent block sections,

and operated in the reverse direction'to open the circuit when that difference of potential is in any way destroyed. Nor doV I limit 1 myselfto any particular form of connection of relay to the tracks, or the transformer to the track as the latter could be connected so that the same polarity at any one instant,

would be the same onl bothsides of the insu-l 'V lated joint in which case the leads 'ofthere lay and armature would be cross-connected such as from thefield of relay the lead 'wire 10 wouldbe connected to rail w1 and the` lead` wire 11 would beconnected to rail gand the lead wiresffrom'armature winding could be connected as follows: Lead wire/12', would be connected torail a: and lead wire l-to rail y1.

i stroyed.

.'WhatI claim as my invention is 1. Inja signaling system, the combination with two block sections the track railsgof one` section bein insulated atits ends from. the track rails o theadjacent block section, oflasignaling current flowing in the railis'fofV each block section, in such directions as to main-A tain a difference of potential between the track rails of the. t'wo block sectionsat the points` ofinsulation, -a relay for each block l section and a relay at each point of insulation the armature of which is operated in one directionby the maintained diiference; of potential and lis o erated in a reverse-direction when the di erenceof potential is del 2. In a signaling system, the combination with a plurality of block sections, both track rails of a block section being insulated at its ends from the track rails of the adjacentblock sections, a signaling current for each block section, the signaling current in one block section flowing in a direction opposite to the How of the signaling current in an adjacent block section whereby a difference of otential is maintained at the ends of two lock sections between the track rails of the two block sections, a relay between two block sections operated by such dierence of potential to close a signaling circuit and operated to open the signaling circuit when such difference of potential is destroyed.

3. In an electric railway system, a source of current of one character, vehicles operated thereby, a circuit for said current formed in part by the track rails and conducting the said current in one direction, the track rails being each divided by insulation'to form block sections, reactance bonds the coils of which are connected across the track rails of the block sections, conductors connecting the middle oints of adjacent coils, a signaling 'current or each block section, flowing in opposite directions lin the track rails, and said signaling currents maintainin a difference of potential at the points of insulation between the track rails of adjacent sections, a

'railway signal controlled fromeach signaling current, and means located at insulation points and operated as to one movement by the dierence of potential between adjacent block sections and operated as to another movement when such difference of potential is destroyed for also'controlling the railway signals. 4.- Ina signaling system, the combination of twofblck sections, both ,track rails of one block section being insulated at its ends from I the track rails of the other section, an alter- 'natin signaling current for each block section t e owof the signaling current in block section at any one instantbeing opposite to the ow'of 'the signaling current in the other block section at the same instant, whereby a dierence of signaling current potential is maintained between the rails at the adjacent e'nd's of the block sections, and a relay device operated as to one of its movements by the saidjdiference of potential and operated as to another of its movements when said difference of potential is destroyed.

5.l In a signaling system, the combination of two block sections, both track rails of one block section being insulated at its ends from the track rails of the other section, an alter- 'hating signaling current for each block section theow of the signaling currentv in o ne block section at any one instant being opposite vtothe flowof the signaling current in the other block section at the same instant,-

whereby a difference of vsignaling current potential is maintained between the rails at the adjacent ends of the block sections, and a relay device comprising 'field and armature coils one terminal of the ield coil being connected-to one rail of a block section and one terminal of the armature coil being' connected with the other rail of the same .block section and the other terminals being connected lwith the track rails of the'other block section, and said relay being operated as to one of its movements by said difference of vpotential and operated as to another of its movements l taining a difference of potential at the ends ol the adjacent block Vsection and between the lines` of rails of the two adjacent block sections, and means located between adjacent block sections and operated as to onev .movement bythe dierence of potential between the lines of rails of adjacent .block sections and operated' as to another movement when su'ch difference of potential is destroyed, and said means controlling railway signals.

7. In a signaling system, the combination with a plurality of block sections, the rails of one section being insulated at its ends from the track rails of the adjacent blocksection, a signaling current flowing in the rails of each block section, a relay connected to both block sections, .and a means whereby the breaking down of an insulated joint will operate a signal that controls the trailic in said block.

8. In a si nalin@ s stem, the-combination with a plura 4ity of block sections, the rails of one section being insulated at its ends froml the track rails of the adjacent block section, of a vsignaling current 'for each block section, a relay connected to both block sections that governs the trafficthrough said sections.

9. In a signaling system,'the combination with a plurality of block sections, the rails of one section being insulated at its ends fro'm `the track rails of the adjacent block section,

of a signaling current for each block section, a' relay connected to .both blockl sections, and a means for 'operating the signal of an adjacent block when a train is in the block. In testimony whereof I have signed my name, to this specification in the presenceof I two subscribed witnesses.

' i LOUIS H. THULLEN;

\ Wltnesses:

A. HERMAN WEGNER, HENRY R.-B-AUER. 

